Continuous form envelopes with gummed flaps and method of making same



E. J. D. STRATTO CONTINUOUS FORM ENVELOPES June 20, 1961 N ETAL 2,988,969

WITH GUMMED FLAPS AND METHOD OF MAKING SAME 3 Sheets-Sheet 1 Filed April 5, 1956 w far/Z6515 June 20, 1961 FIE. 5

E. CONTINUOUS FO Filed April 5, 1956 J D. STRATTON ET AL RM ENVELOPES WITH GUMMED FLAPS AND METHOD OF MAKING SAME 5 Sheets-Sheet 2 J n 0, 1 1 E J D. STRATTON ETAL CONTINUOUS FRM ENVELOPES WITH GUMMED FLAP AND METHOD OF MAKING SAME Filed April 5, 1956 3 Sheets-Sheet 3 United States Patent 2,988,969 CONTINUOUS FORM NVELOPES WITH GUMNIED FLAPS AND METHOD OF MAKING SAME Edwin J. D. Stratton and Donald J. Steidinger, Deep River, Conn., assignors to Uarco, Incorporated, a corporation of Illinois Filed Apr. 5, 1956, Ser. No. 576,478 8 Claims. (Cl. 9361) This invention relates to an assembly of seriesconnected envelopes, and more particularly to a method of applying adhesive to the closure flaps of such an assembly.

The primary object of the present invention is to provide a new and improved method of applying adhesive to the closure flaps of envelopes in continuous strip form. Heretofore, glue in a fluid: state was deposited upon the closure flaps which. necessitated a drying operation before the envelope strips were completed and ready for packaging and shipment. The. present method eliminates this time consuming operation, and it simplifies and facilitates the formation of series-connected envelopes with sealing flaps.

Another object is to provide an improved method of forming. top flap envelopes in continuous strip form.

A further object is to provide an improved method of forming an assembly of series-connected envelopes having sealing adhesive on their closure flaps.

Another object is to provide an envelope which has a. closure flap having. a strip of gummed tape heat-sealed thereon.

The preferred, embodiment and. the preferred method of, the present invention are illustrated in the accompanying drawings, in. which:

FIG. 1 is a diagrammatic perspective view illustrating the steps in the preferred method. of forming an assembly of seriesconnected. envelopes;

FIG. 2, av plan view of an. envelope of the assembly showing its front portion;

FIG. 3., a plan view of the envelope of the assembly showing its. back portion;

FIG. 4,. a sectional view taken as indicated on. line.

4-4 of FIG. 3;

FIG. 5, a fragmentary plan view of the webs of envelope sheet material. in juxtaposition showing the method steps in the formation of the envelope assembly;

FIG. 6, a plan. view taken from the underside of FIG. 5;

FIG. 7, a diagrammatic perspective view illustrating the steps in the method of forming an assembly of sideflap, series-connected envelopes;

FIG. 8, a fragmentary plan view of a portion of the assembly of side-flap, series-connected. envelopes;

FIG. 9, a plan view of a single, sideflap envelope; and

FIG. 10, a sectional view takenv as indicated on line 10 of FIG. 9.

The assembly of envelopes formed. by the method of the present invention is frequently used in modern auto matic business machines, such as typewriters and addressographs, where it is desired to imprint addresses quickly and accurately upon a series of envelopes. Such envelopes in continuous strip form are economical, and their use results in great savings of time and labor, because the strip may be continuously fed through the business machine.

One of the embodiments and methods is illustrated by the diagrammatic. view in FIG. 1v of an assembly of top flap envelopes in continuous form. sealing adhesive is applied to the envelope fiaps as. the individual envelopes are being formed from a pair of juxtaposed webs of envelope sheetmaterial. The webs are joined at appropriate places to form a series of alter- In this assembly, a

nately spaced, transversely extending envelope pockets 13 and envelope flaps 14, as best seen in FIGS. 4 and 6. It is contemplated by the present invention that the assembly is contemplated by the present invention that the assembly of envelopes may be formed in some other manner, and that an adhesive be later applied to the closure flaps in accordance with the present disclosure.

The diagrammatic view in FIG. 1 illustrates the preferred method of forming the assembly of seriesconnected, top-flap envelopes. A pair of webs, generally designated 15 and 16, of envelope sheet material are unwound from ordinary r011 stock and superposed one on the other. One of the webs may have an entire face coated with a heat-sealing adhesive, or it may have bands of heat-sealing adhesive (sometimes simply called hot melt material) placed upon it by the location hot melt method, so that when the two Webs are subjected to heat and pressure in appropriate places, they will be secured together to form the envelope pockets 13.

In FIG. 1, the heat-sealing adhesive has been applied to the lower face of the web 15 by the location hot-melt method. It is preferred that the heat-sealing adhesive be placed so as to form a hot melt pattern including a pair of longitudinally extending bands 17 and 18, and a series of relatively wide, transversely extending bands 20 which are spaced longitudinally of the web 15. The size and position of the bands, of course, may be varied in accordance with the type and size of envelopes which are to be formed. y

Before the two webs are brought into juxtaposition, the web 16 is successively die-cut at longitudinally spaced points, and a series of die-cut slugs are removed so that a number of similar transversely extending die-cut portions or openings 21 are formed in the web 16. The die-cut portions 21 are preferably similar to each other and equidistantly spaced longitudinally of the web 16..

After the die-cut slugs are removed, a pair of longit.u.

dinally extending marginal edge portions 22 and 23 re.- mains at the sides of the web 16 which forms a ladderlike configuration in the web 16 before it is brought together with the web 15. The marginal edge portions at opposite ends of each of the die-cut portions 21 are left with sufficient Width so that the web 16 will still have considerable strength and resistance to tearing as it is advanced with the web 15.

As the webs 15 and 16 are brought together, they are. positioned with respect to each other so that a trans versely extending segment of each of the transverse bands. 20 is exposed at the forward edge of each of the die-cut portions 21, as best seen in FIG. 6. The marginal edge portions. 22 and 23 are preferably positioned so as to. cover each of the longitudinally extending side bands of adhesive 17 and 18.

After the webs 15 and 16 have been correctly positioned against each other, they are advanced by a heat-sealing station which applies heat and pressure to the regions.

above and below the transverse band 20 to form a bottom 24 in each successivev pocket 13. As shown in FIG. 1,

this heat-sealing station may include an upper heat-seal cent the heat-seal bars 25 and 26 to feed lengthsof tape 30 from a supply roll 31 transversely of the advancing webs 15 and 16. The tape is preferably provided with a moisture sensitive adhesive 32' on its exposed face, and may have a heat-seal adhesive 33 on its sealed or flapcontacting face.

Although it is contemplated by the invention that the webs may be continuously advanced, it is preferred that an intermittent drive be provided. Both the heat-seal bars 25 and 26 and the feed rolls 27 and 28 are operated in timed relation to the drive means advancing the Webs and 16. Each time that the webs 15 and 16 start their forward advance, the heat-seal bar 25 is in its upward inoperative position, and the feed rolls 27 and 28 advance a tape length 30 to a position on the top face of the lower heat-seal bar 26. The webs 15 and 16 are then brought to a halt so as to position one of the transverse bands 20 of heat-seal material between opposed faces of the bars and 26. At this time the portion of the transverse band 20 which is exposed at the forward edge of each of the die-cut portions 21 is positioned above the length of tape resting on the lower heat-seal bar 26.

The heat-seal bars 25 and 26 are then brought together, and heat and pressure is applied to the transverse band 20 of heat-seal adhesive to form the bottom 24 of the envelope pocket 13 and to adhere the length of tape 30 to the envelope fiap 14. As the heat-sealing operation is performed, a cutting member 34, preferably operating in timed relation with the bars 25 and 26, severs the length of tape 30 from the supply roll 31.

At the same time that the bottom 24 of the envelope pocket 13 is being formed, additional heating elements may be provided to close sides and 36 of that envelope pocket. This sealing operation is preferably performed by two pairs of heat-seal bars 37, 38 and 40, 41, each pair of which is oppositely disposed above and below the side bands of adhesive 17 and 18, respectively, in the marginal edge portions 22 and 23 of the envelope assembly, as best seen in FIG. 1. Preferably, the heat-seal bars 37, 38 and 40, 41 are spaced forwardly from the bars 25 and 26, one envelope length in the envelope assembly. All three pairs of heat-seal bars, 25, 26, 37, 38 and 40, 41, operate together and in timed relation to the intermittent advancement of the envelope assembly. Thus the continuous envelope assembly is advanced a predetermined distance, depending upon the size of the envelope being formed, the assembly is then stopped, and the cooperating heat-seal bars are pressed together to seal appropriate portions of the advancing webs, and successively form pockets 13. Each pair of cooperating heat-seal bars is then moved apart, and the intermittent drive advances the envelope assembly another envelope length so that the process can again be repeated.

It is next preferred that the opposite ends of the envelope flaps 14 be die-cut as at 42 and 43 to give the desired shape to each flap. As best seen in FIG. 6, the die-cutting operation preferably produces a triangular opening and removes end portions of the flap 14 and tape 30 and small inner segments from the marginal edge portions 22 and 23. The die-cut areas are preferably located so that a pair of projections 44 and 45 remain in the marginal edge portions 22 and 23 and extend across a line of fold 46 which is later impressed in each envelope of the assembly. In the completed envelope, as illustrated in FIGS. 2, 3 and 4, the projections 44 and 45 strengthen each individual envelope at the extremities of its line of fold 46.

The ladder-like web 16 is most apt to be torn or broken prior to the time that it is joined to the Web 15. The web 16 generally tears at 22a or 23a in its marginal edge portions 22 and 23 at opposite ends of the die-cut portion 21. For this reason it is desirable to maintain these marginal edge portions at 22a and 23a as wide as possible to lend added strength to the web 16. The present method is particularly well adapted to assure this important feature since the die-cuts at 42 and 43 later remove inner segments of the edge portions 22 and 23 and form projections 44 and 45 in each envelope of the completed assembly. It should also be noted that by retaining the width of web 16 at 22a and 23a during heat-sealing operations, the bands 17 and 18 of heat-seal adhesive are completely covered, and the lower heat-seal bar 25 cannot adhere to the advancing webs of sheet material and cause them to break or tear.

The marginal edge portions 22 and 23 are next preferably trimmed as indicated at 47 and 48, and each marginal edge portion is provided with a series of equally spaced apertures 50 which form a feed track so that the completed envelope assembly can be conveniently advanced by the pinwheel feed of a writing machine.

Suitable means are then provided for detaching the marginal edge portions of the envelope assembly from the successively connected envelopes, and suitable means are also provided for detachably connecting each envelope from the envelopes adjacent it. As herein shown, lines of weakening 51 and 52 are provided to separate the envelope assembly from each of the marginal edge portions 22 and 23, and lines of weakening 53 are provided between each of the envelope flaps 14 and eachbottom 24 of the next adjacent envelope so that they may be conveniently separated when desired.

FIG. 7 is a diagrammatic illustration of the method of applying gummed tape to the closure flaps of an assembly of series-connected, side-flap envelopes. An upper web 54 of envelope sheet material is preferably provided with an appropriate pattern of heat-sealing adhesive by the location hot-melt printing method. As herein shown, a series of equally spaced transversely extending bands of adhesive 55 may be applied to the under-face of the upper web 54 and be joined at one end to a longitudinally extending band of heat-sealing adhesive 56, as best seen in FIG. 7. A second longitudinally extending band of heat-sealing adhesive 57 is preferably provided in a marginal edge portion 58 of the upper web 54, and is spaced from each of the adjacent ends of the transverse bands 55. A lower web 60, which is slightly narrower than the upper web 54, is next brought into juxtaposition with the upper web 54 so that the marginal edge portions adjacent the longitudinal band 56 are substantially in align- I ment. Thus, the marginal edge portion 58 projects outwardly beyond a marginal edge 61 of the lower web 60.

The two webs in juxtaposition are then advanced between a pair of opposed cooperating heat-seal bars 62 and 63. The webs may either be intermittently advanced or continuously advanced, but as herein shown, it is preferred that their advance be intermittent. The heat-seal bars 62 and 63 operate in timed relation to the intermittent advance of the two webs 54 and 60. When the bars 62 and 63 are pressed together, a sealing pattern is eflected which closes a bottom edge 64 of a side-flap envelope, generally designated 65, and a pair of side edges 66 and 67 of an adjacent pair of side-flap envelopes 65. When the next envelope is advanced beneath the bars 62 and 63, its bottom and its remaining side edge is sealed, and

in addition, a side-edge of thev envelope next to be advanced beneath the bars has one of its side edges sealed.

A pair of feed rolls 68 and 70 are diagrammatically illustrated in FIG. 7, and these wheels are driven in timed relation to the intermittent advance of the assembly of envelopes. The end of a supply roll 71 of gummed tape 69, similar to the gummed tape described above, is threaded through the feed rolls 68 and 70 and deposited in a continuous strip upon the longitudinal band of hcat sealing adhesive 57 on the marginal edge portions 58. The gummed tape is intermittently fed to a position between a pair of opposed heat-seal bars 72 and 73 which,

at 76, to form successive sideflaps 77 for each envelope I g in the assembly. Suitable means are also provided in the form of lines of weakening 78, 80 and 81 to permit detachment of the feed-tracks and to permit the individual envelopes to be separated from each other when desired. .FIGS. 9 and 10 illustrate the side-flap envelope as it appears after separation from the assembly.

The strip of series-connected, side-flap envelopes is then ready to be placed in the desired automatic business machine, and the successive envelopes may be addressed by merely advancing the strip through the machine.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom, for some: modifications will be obvious to those skilled in the art.

We claim:

1. The method of forming an assembly of series-connected detachable envelopes, comprising the steps of: die cutting a first web of envelope material to provide said first web with a series of longitudinally spaced transversely extending out-out portions; advancing said first web in timed relation into juxtaposition with an advancing second web of envelope material to form the fronts and backs respectively of series-connected envelopes with the fronts having a series of transversely extending exposed flaps; adhering adjacent fronts and backs together successively along narrow peripheral bands to form a series of transversely opening envelope pockets; feeding strips of moisture-sensitive gummed tape one onto each flap in timed relation to the advance of the webs, each of said strips being fed so as to have a moisture-sensitive gummed side exposed; and heat sealing each of said strips to its respective flap in timed relation to the advance of the webs to adapt the individual envelopes for sealing when separated from the assembly.

2. The method of forming an assembly of series-connected detachable envelopes, comprising the steps of: applying heat-sealing adhesive to a first web of envelope material in a U-shaped, three-sided pattern corresponding to the normally closed edges of an envelope pocket, the medial side of the pattern extending transversely of said first web, said pattern being successively applied to the web at longitudinally spaced points; die-cutting a second web of envelope material to provide a series of longitudinally spaced, transversely extending cut-out portions; advancing said pair of webs in timed relation into juxtaposition to form the fronts and backs respectively of series-connected envelopes with the fronts having a series of flaps exposed by the cut-out portions, said cut-out portions also exposing heat-sealing adhesive of the medial side of said pattern; feeding strips of moisture-sensitive gummed tape one onto the exposed adhesive of the medial side of each of said patterns in timed relation to the advance of said webs, each of said strips being fed so as to have a moisture-sensitive side exposed; and applying heat and pressure successively to each of said three-sided patterns of adhesive in timed relation to the advance of the webs to adhere each of the strips of tape to its respective flap and to form a series of envelope pockets having transversely extending openings.

3. The method of claim 2, including the steps of ad vancing the juxtaposed webs intermittently, feeding the strips of gummed tape in timed relation to the intermittent advance of the juxtaposed webs, and applying heat and pressure in timed relation to the intermittent advance of said webs to form the envelope pockets and adhere each strip of the gummed tape to its respective flap.

4. The method of forming an assembly of series-con nected detachable envelopes, comprising the steps of: applying heat-sealing adhesive to one face of a first web of envelope material; die-cutting a second web of envelope material to provide a series of longitudinally spaced, transversely extending cut-out portions; advancing said pair of webs in timed relation into juxtaposition to form the fronts and backs respectively of series-conpected envelopes with the fronts having a series of flaps exposed by the cut-out portions including portions of said one face; feeding strips of moisture-sensitive gummed tape one onto each of said flaps in timed relation to the advance of the webs, each of said strips being fed so as to have the moisture-sensitive side exposed on said portions of the one face; and applying heat and pressure successively to said webs in appropriate places to seal said gummed tape to each flap closure and to form a series of envelope pockets, each pocket extending transversely of the assembly.

5. The method of applying moisture-sensitive adhesive to the exposed flaps of a strip of envelopes in continuous form, comprising the steps of: advancing the strip of envelopes past a feeding station; feeding strips of moisture-sensitive gummed tape one onto each exposed flap in timed relation to the advance of the strip of envelopes, each of said strips being fed so as to have a moisture-sensitive gummed side exposed; and heat sealing each of the strips to its respective flap to adapt the individual envelopes for sealing when separated from the assembly.

6. The method of applying moisture-sensitive adhesive to the exposed flaps of a strip of envelopes in continuous form, comprising the steps of: intermittently advancing the strip of envelopes past a feeding station; feeding strips of moisture-sensitive gummed tape transversely of the path of advance of said strip of envelopes in timed relation thereto, one strip of tape being fed onto each exposed envelope flap so as to have a tape-face provided with heat sensitive adhesive adjacent the flap and a tape-face with moisture sensitive adhesive exposed; applying heat and pressure to each strip of gummed tape and the adjacent flap portions each time the strip of envelopes is stopped during its intermittent advance to adhere each of the strips of gummed tape to its respective flap; and trimming the ends of each of the strips of gummed tape in timed relation to the advance of the strip of envelopes to conform each strip of tape to the contour of its flap.

7. The method of applying moisture-sensitive adhesive to the exposed flaps of a strip of envelopes in continuous form, comprising the steps of: advancing the strip of envelopes past a feeding station; applying heat-sealing adhesive across the outer marginal edge of each of the exposed flaps of the strip of envelopes; feeding strips of moisture-sensitive gummed tape one onto each exposed flap in timed relation to the advance of the strip of envelopes so that each of the strips of gummed tape is in juxtaposition with the heat-sealing adhesive and has a moisture-sensitive gummed side exposed; and heat-sealing each of the strips of gummed tape to its respective flap to adapt the individual envelopes for sealing when separated from the assembly.

8. The method of applying moisture-sensitive adhesive to the closure flaps of a continuous form envelope assembly having envelopes with transverse envelope pocket openings and transverse closure flaps for the envelope pocket openings, comprising the steps of: advancing the envelope assembly past a feeding station; positioning strips of moisture-sensitive gummed tape transversely of the envelope assembly, one onto each closure flap with a moisture-sensitive gummed side of each strip of gummed tape exposed; and heat-sealing each of the strips of gummed tape to its respective closure flap to adapt the individual envelopes for sealing when separated from the assembly.

References Cited in the file of this patent UNITED STATES PATENTS 1,702,115 Gurwick Feb. 12, 1929 2,342,702 Sherman Feb. 29, 1944 2,351,805 Bonnaire June 20, 1944 2,372,008 Krueger Mar. 20, 1945 2,722,369 Renter Nov. 1, 1955 

